Device and method for removing gas and debris during the photodisruption of stromal tissue

ABSTRACT

A device for removing gas and debris from the stroma of an eye during ophthalmic laser surgery includes a contact lens that is formed with a recessed chamber. The device also includes a suction pump that is connected in fluid communication with the recessed chamber. In operation, the stroma is stabilized in the recessed chamber of the contact lens and an opening into the stroma is created. This opening is created either by the laser beam, or by a probe that is mounted on the contact lens to penetrate the stroma while the stroma is stabilized in the recessed chamber of the contact lens. Then, simultaneously or subsequently, as a laser beam is directed through the contact lens to photodisrupt tissue in the stroma the suction pump is activated to aspirate the resultant gas and debris through the opening and out of the stroma.

FIELD OF THE INVENTION

[0001] The present invention pertains generally to devices which areuseful in ophthalmic laser surgery. More particularly, the presentinvention pertains to contact lenses which will stabilize the eye of apatient during ophthalmic surgery. The present invention isparticularly, but not exclusively, useful as a contact lens whichstabilizes the eye and also aspirates the gas and debris that is createdas stromal tissue is photodisrupted during intrastroma ophthalmic lasersurgery.

BACKGROUND OF THE INVENTION

[0002] During laser surgery, the interaction of the laser beam with bodytissue involves a phenomenon which is generally referred to asphotodisruption. The result of photodisruption on the affected tissue isreally three-fold. In part, the tissue is vaporized. In part, there aremechanical effects on the tissue which become manifest in the tearing,separation and division of the affected tissue. Finally, there may bethermal effects which include charring and scorching of the affectedtissue. The consequences are mixed. Along with the beneficial andintended consequences for a particular surgical procedure (i.e. thecutting or removing of tissue) there are also unwanted consequences ofphotodisruption. These unwanted consequences typically result from thegeneration of gas and tissue debris which have the potential to disruptthe surgical procedure. Preferably, the unwanted gas and debris can beremoved from the surgical site.

[0003] For laser surgical procedures which are accomplished on externalor exposed tissue, the problem of removing gas and debris from thesurgical site is relatively easily solved. In this case, the gas willdissipate and the debris can be easily washed away or aspirated. Thecase is quite different, however, where internal tissue is involved.Specifically, in the case of intrastromal procedures wherein a specificvolume of internal stromal tissue is to be photodisrupted, there is areal concern about how to best remove the unwanted gas and debris.Clearly, this gas and debris needs to be removed for several reasons.These reasons include: 1) the need to reduce the unwanted build up ofgas pressure in the stroma during a surgical procedure; and, 2) the needto remove debris particles and obstructions which could otherwiseinterfere with the laser beam during subsequent photodisruption ofadditional stromal tissue. In order to address these needs, reliance onsomething more than the body's own ability to resorb the affected tissueis necessary.

[0004] In light of the above, it is an object of the present inventionto provide a device which will effectively reduce the unwanted build upof gas pressure in the stroma during ophthalmic laser surgery. Anotherobject of the present invention is to provide a device which willeffectively remove debris particles and obstructions from the stromawhich could otherwise interfere with the subsequent photodisruption ofadditional tissue. Yet another object of the present invention is toprovide a device for removing the gas and debris that results during thephotodisruption of stromal tissue which is easy to use, relativelysimple to manufacture, and comparatively cost effective.

SUMMARY OF THE PREFERRED EMBODIMENTS

[0005] A device for removing gas and debris from the stroma of an eyeduring intrastromal ophthalmic laser surgery includes a contact lens anda suction apparatus which is interconnected with the contact lens.Further, the contact lens is formed with a recessed chamber, and thesuction apparatus is connected in fluid communication with the recessedchamber. With this combination, when the recessed chamber of the contactlens is positioned over the eye, and the suction apparatus is activated,the cornea of the eye is drawn into the recessed chamber to hold thecornea against the contact lens. This action also stabilizes the eyeduring subsequent laser surgery.

[0006] Once the cornea of the eye has been stabilized by the contactlens, a laser source can be activated to generate a laser beam. Forpurposes of the present invention, this laser beam will be directedthrough the contact lens to perform the desired intrastromal ophthalmiclaser surgery. When doing so, stromal tissue is photodisrupted by thelaser beam in a predetermined manner. It is well known, however, that asstromal tissue is photodisrupted by a laser beam, gas and debris areformed as by-products in the stroma. To compensate for this result, andavoid the unwanted consequences which can ensue if nothing is done, thegas and debris need to be removed as quickly as possible. In accordancewith the present invention, the removal of gas and debris from insidethe stroma can be accomplished by aspiration in either of two ways. Forboth of these ways, a fluid communication channel into the stroma needsto be created.

[0007] With one embodiment of the present invention for removing gas anddebris from the stroma during intrastromal ophthalmic laser surgery, thelaser system itself is used to create an external opening into thestroma. Importantly, in addition to establishing a fluid communicationchannel with the interior of the stroma, this external opening needs toremain in fluid communication with the recessed chamber during thesurgical procedure. Stated in the negative, the external opening intothe stroma can not be created wherever there is a contact between thecornea and the contact lens that would obstruct the external opening.Then, with the opening undisturbed, subsequent activation of the lasersystem can be accomplished in a manner which will place the gas anddebris that results from the photodisruption of tissue in fluidcommunication with the external opening. The external opening, ofcourse, will also be in fluid communication with the recessed chamber,and the recessed chamber will be in fluid communication with the suctionapparatus. Accordingly, the suction apparatus can aspirate the gas anddebris from the stroma and thereby remove this material from the eye.

[0008] With another embodiment of the present invention for removing gasand debris from the stroma during intrastromal ophthalmic laser surgery,a hollow probe is mounted on the contact lens to extend into therecessed chamber. Thus, for this embodiment of the present invention,the suction apparatus is connected in fluid communication with therecessed chamber through the probe. With this configuration, when therecessed chamber of the contact lens is positioned over the cornea, andthe suction device is activated to draw the cornea into the recessedchamber, the probe will penetrate into the stroma. Subsequent activationof the laser system will then need to begin at the tip of the probe andcontinue from there through the stroma as desired. In this manner, thetip of the probe will remain in fluid communication with the stromaltissue that is being photodisrupted so that the resultant gas and debriscan be removed from the eye.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The novel features of this invention, as well as the inventionitself, both as to its structure and its operation, will be bestunderstood from the accompanying drawings, taken in conjunction with theaccompanying description, in which similar reference characters refer tosimilar parts, and in which:

[0010]FIG. 1 is a perspective view of the device for removing gas anddebris from the stroma in accordance with the present invention;

[0011]FIG. 2 is a perspective view of the contact lens and suctionapparatus of the present invention, shown detached and isolated from thelaser system;

[0012]FIG. 3A is a cross sectional view of the contact lens of oneembodiment of the present invention as seen along the line 3-3 in FIG.2;

[0013]FIG. 3B is a view of the contact lens as seen in FIG. 3A with thecontact lens in contact with the cornea of an eye;

[0014]FIG. 4A is a cross sectional view of another embodiment of thecontact lens of the present invention as seen along the line 3-3 in FIG.2; and

[0015]FIG. 4B is a view of the contact lens as seen in FIG. 4A with thecontact lens in contact with the cornea of an eye.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0016] Referring initially to FIG. 1, a device for removing gas anddebris from the eye during intrastromal ophthalmic laser surgery isshown and generally designated 10. As shown, the device 10 includes alaser system 12 which is used to generate a laser beam 14 that can beused for the particular surgical procedure that is to be performed. Asintended for the present invention, the laser beam 14 will preferably bea pulsed laser beam which includes a train of pulses. Further, dependingon the particular surgical procedure that is to be performed, and thedesires of the attending physician, the wavelength for light in thelaser beam 14 can be selected from several ranges of wavelengths, andeach pulse in the beam 14 can have a duration that is in the range ofpicoseconds or femptoseconds. FIG. 1 also shows that the device 10includes a retainer 16 which is used to hold a contact lens 18 in apredetermined spatial relationship with the laser system 12. Forpurposes of the present invention, the contact lens 18 is preferably arigid structure which is made of glass or a clear medical grade plastic.

[0017] As intended for the present invention, the laser beam 14 isdirected through the contact lens 18 and toward the eye 20 of a patient.More specifically, the laser beam 14 is directed into the stroma 22 ofthe cornea 24 of eye 20, where its focal point is moved along apredetermined path to photodisrupt stromal tissue. As mentioned above,the by-products of this photodisruption include gas and debris whichneeds to be removed from the stroma 22.

[0018] In both FIGS. 1 and 2 it will be seen that the device 10 alsoincludes a suction pump 26 which is connected in fluid communicationwith the retainer 16 by a first suction line 28. Additionally, FIGS. 1and 2 shown that the device 10 may include a second suction line 30which directly connects the suction pump 26 in fluid communication withthe contact lens 18. The particulars of these connections, and thedetailed structure of the contact lens 18 will be best appreciated byreference to FIGS. 3A, 3B, 4A and 4B.

[0019]FIG. 3A shows that a contact lens 18 in accordance with thepresent invention has a substantially flat anterior surface 32, and asubstantially flat aplanation surface 34. As shown, the anterior surface32 is generally parallel to the aplanation surface 34. It is to beappreciated, however, that for an alternate embodiment of the presentinvention, the anterior surface 32 and the aplanation surface 34 may becurved to conform with the radius of curvature of the eye. In any event,the resultant optical interaction between these surfaces 32, 34 is thesame for all configurations. Additionally, FIG. 3A shows that thecontact lens 18 includes a skirt 36 which extends outwardly from theaplanation surface 34, and surrounds the aplanation surface 34 to definea recessed chamber 38 which is located between the aplanation surface 34and the skirt 36. In further detail, FIG. 3A shows that in the recessedchamber 38 at the interface between the skirt 36 and the aplanationsurface 34, the contact lens 18 is formed with a groove 40.

[0020] Still referring to FIG. 3A, it will be seen that the firstsuction line 28 is connected with the retainer 16 and is placed in fluidcommunication with the groove 40 in recessed chamber 38 via a passageway42. With this connection it will be appreciated that the suction pump 26is also in fluid communication with the recessed chamber 38.Accordingly, when the contact lens 18 is positioned on the eye 20 withthe recessed chamber 38 against the cornea 24, and a partial vacuum isdrawn in the recessed chamber 38 by the suction pump 26, the cornea 24will be drawn toward and flattened against the aplanation surface 34 ofthe lens 18 substantially as shown in FIG. 3B. In this configuration(FIG. 3B), intrastromal ophthalmic laser surgery can be performed on thestroma 22.

[0021] As suggested in FIG. 3B, with the cornea 24 stabilized inrecessed chamber 38 of contact lens 18, an external opening 44 in theanterior surface of cornea 24 can be made which will establish fluidcommunication with the interior of the stroma 22. Accordingly, asintrastromal laser surgery proceeds into the stroma 22 from externalopening 44, the gas and debris 46 which results from photodisruption ofthe stromal tissue will be aspirated by the action of the suction pump26. Specifically, for this embodiment of the device 10, the gas anddebris 46 from inside the stroma 22 will be aspirated through theexternal opening 44 and into the recessed chamber 38. The gas and debris46 will then be further aspirated from the recessed chamber 38 throughthe passageway 42 and first suction line 28 into a collection vial (notshown) in the suction pump 26. As will be appreciated by the skilledartisan, for this embodiment of the present invention, it is importantthat the opening 44 remain in fluid communication with the recessedchamber 38. This condition can, of course, be insured by firststabilizing the contact lens 18 on the eye 20, and then appropriatelyselecting the location for the external opening 44 on a portion of theanterior surface of the cornea 24 that is not in direct contact with thelens 18.

[0022] Another embodiment for the contact lens 18′ of the presentinvention is shown in FIG. 4A. The specific difference between thecontact lens 18 of FIG. 3A, and the contact lens 18′ of FIG. 4A, is thatfor the embodiment shown in FIG. 4A, there is a second suction line 30which is connected in fluid communication with a hollow probe 48. Morespecifically, as shown in FIG. 4A, the probe 48 is mounted on thecontact lens 18′ to extend from the aplanation surface 34 and into therecessed chamber 38. Accordingly, when the contact lens 18′ ispositioned over the eye 20, and the suction pump 26 is activated tocreate a partial vacuum in the recessed chamber 38, the cornea 24 willbe drawn into the recessed chamber 38. This will then cause the tip 50of probe 48 to puncture or penetrate the anterior surface of the cornea24. With this penetration, the tip 50 of probe 48 creates an externalopening 52 through which it will become embedded into the stroma 22.Because the probe 48 is hollow, the suction pump 26 is in direct fluidcommunication with the exposed tip 50 of probe 48. Consequently, bybeginning an intrastromal laser surgery at the tip 50, and thereafterprogressing contiguously therefrom through the stroma 22, any gas anddebris 46 which is created during surgery can be effectively aspirated.Specifically, this gas and debris 46 will be aspirated through the probe48, and through the second suction line 30, back to a collection vial(not shown) in the suction pump 26.

[0023] While the particular Device and Method for Removing Gas andDebris During the Photodisruption of Stromal Tissue as herein shown anddisclosed in detail is fully capable of obtaining the objects andproviding the advantages herein before stated, it is to be understoodthat it is merely illustrative of the presently preferred embodiments ofthe invention and that no limitations are intended to the details ofconstruction or design herein shown other than as described in theappended claims.

What is claimed is:
 1. A device for removing gas and debris caused bythe photodisruption of stromal tissue during ophthalmic laser surgerywhich comprises: a contact lens formed with a recessed chamber forreceiving and stabilizing the cornea of an eye therein; a laser systemfor generating a laser beam, said laser beam being directed through saidcontact lens to photodisrupt tissue in the stroma of the cornea; acutting means for creating an external opening into the stroma to accessthe gas and debris caused by the photodisruption of tissue; and asuction means for aspirating the gas and debris from the stroma throughthe opening and through the lens for removal therefrom.
 2. A device asrecited in claim 1 wherein the contact lens comprises: a lens memberhaving an anterior surface and an aplanation surface, the aplanationsurface being substantially parallel to the anterior surface; a skirtsurrounding the aplanation surface and extending outwardly therefrom todefine the recessed chamber therebetween; and a first suction line forconnecting the suction means in fluid communication with the recessedchamber to create a partial vacuum therein between the aplanationsurface and the cornea of the eye to stabilize the cornea against thecontact lens.
 3. A device as recited in claim 2 wherein the skirt isformed with a groove to establish a suction channel between theaplanation surface and the skirt.
 4. A device as recited in claim 3wherein the first suction line is connected in fluid communication withthe recessed chamber through the suction channel.
 5. A device as recitedin claim 1 wherein the cutting means for creating the external openinginto the stroma is the laser system.
 6. A device as recited in claim 5wherein the suction means is in fluid communication with the recessedchamber of the contact lens, and the recessed chamber is in fluidcommunication with the external opening into the stroma.
 7. A device asrecited in claim 1 wherein the cutting means for creating the externalopening into the stroma is a probe, the probe being mounted on thecontact lens, and wherein the device further comprises a second suctionline for connecting the probe in fluid communication with the suctionmeans.
 8. A device as recited in claim 1 wherein the contact lens ismade of a clear medical grade plastic.
 9. A device for removing gas anddebris caused by the photodisruption of stromal tissue during ophthalmiclaser surgery which comprises: a structure means for stabilizing thecornea of an bye; a cutting means for creating an external opening intothe stroma of the cornea to access the gas and debris caused by thephotodisruption of tissue; a conduit means for establishing a fluidchannel, the fluid channel being in fluid communication with the openinginto the stroma; and a suction means in fluid communication with thefluid channel for aspirating the gas and debris from the stroma throughthe opening and through the fluid channel for removal of the gas anddebris from the stroma.
 10. A device as recited in claim 9 wherein thestructure means is a contact lens comprising: a lens member having ananterior surface and an aplanation surface, the aplanation surface beingsubstantially parallel to the anterior surface; a skirt surrounding theaplanation surface and extending outwardly therefrom to define arecessed chamber therebetween; and a first suction line for connectingthe suction means in fluid communication with the recessed chamber tocreate a partial vacuum therein between the aplanation surface and thecornea of the eye to stabilize the cornea against the contact lens. 11.A device as recited in claim 10 wherein the skirt is formed with agroove to establish a suction channel between the aplanation surface andthe skirt.
 12. A device as recited in claim 11 wherein the first suctionline is connected in fluid communication with the recessed chamberthrough the suction channel.
 13. A device as recited in claim 10 whereinthe conduit means is the recessed chamber and the cutting means forcreating the external opening into the stroma is the laser system.
 14. Adevice as recited in claim 13 wherein the suction means is in fluidcommunication with the recessed chamber of the contact lens, and therecessed chamber is in fluid communication with the opening into thestroma.
 15. A device as recited in claim 10 wherein the cutting meansfor creating the external opening into the stroma is a probe, the probebeing mounted on the contact lens, and wherein the device furthercomprises a second suction line for connecting the probe in fluidcommunication with the suction means.
 16. A device as recited in claim15 wherein the conduit means is the probe.
 17. A method for removing gasand debris from the stroma caused by the photodisruption of stromaltissue during ophthalmic laser surgery which comprises the steps of:stabilizing the cornea of an eye with a contact lens, the contact lensbeing formed with a recessed chamber for receiving the cornea therein;activating a laser system to generate a laser beam, the laser beam beingdirected through the contact lens to photodisrupt tissue in the stromaof the cornea; creating an external opening into the stroma to accessthe gas and debris caused by the photodisruption of tissue; andaspirating the gas and debris from the stroma through the externalopening and through the lens for removal therefrom.
 18. A method asrecited in claim 17 wherein the creating step is accomplished with thelaser system.
 19. A method as recited in claim 17 wherein the creatingstep is accomplished with a probe mounted on the contact lens with theprobe extending into the recessed chamber of the contact lens.
 20. Amethod as recited in claim 19 wherein the contact lens is made of aclear medical grade plastic.